The purpose of the research was to explore the causal model of adolescent attachment on emotion regulation.Participants in this research were 575 eight-grade students, 295 male and 280 female, from the north part of Taiwan including Shin-Jaw City. The Interpersonal Interaction Scale, the Knowing Myself Scale, the Knowing Others Scale, the My Feeling Scale and the Emotion Regulation Scale were administered. Theresults indicated that the model fit the data collected, and that the exogenous variable (adolescent attachment (had both direct and indirect effects on the endogenous variable (emotion regulation.( The self-representation,a mediator variable in the model, had the most powerful influence in the indirect relationship. The results were helpful (a) in understanding the ways attachment influenced emotion regulation, (b) for developing training courses for emotion management, (c) in further testing attachment theory, (d) for school counselors,and (e) in understanding the need to remind parents of the importance of parenting interaction.